Your sleep habits and your eating habits could tell you how much more (or less) sleep you need.

Everyone's heard the general advice to get eight hours of sleep per night. But sleep specialist and author Dr. Michael Breus told INSIDER that number is a more of a general benchmark — and sleep needs can vary from person to person.

"The amount of sleep I need might be very different than the amount of sleep that you need," he said. "Depending upon what stage in life you're in — if you're pregnant, if you're a senior, if you've got medical complications — the amount of sleep you need can be actually very different."

How can you tell if you're getting the right amount for you?

Breus said you can start by asking yourself these five simple questions. If you answer no to all or most of them, you're probably well-rested. But if you answer yes to at least two, he said, you likely need more sleep.

1. Do you fall asleep before your head hits the pillow?

When you're truly well rested, you won't be able to doze off instantaneously.

"If you fall asleep as your head hits the pillow, that's generally not a good sign," Breus said. "Sleep is a process — it's kind of like slowly pulling your foot off the gas and slowly putting your foot on the brake. It should take anywhere from 15 to 25 minutes to fall asleep. So when you fall asleep in under five minutes, that means you're sleep deprived."

2. Do you hit the snooze button more than twice?

Generally, a person who gets enough sleep should be able to wake up without an alarm, Dr. Cindy Geyer previously explained to INSIDER. Sadly, most of us don't get to choose when we wake up, so we rely on one. But take note if you're overusing your snooze button: Breus said multiple rounds of snoozing are "definitely a sign that you are sleep deprived."

3. Do you sleep in on the weekends?

Breus explained that sleeping in on the weekends is another sign that you're not getting enough rest.

Ideally, your sleep schedule should be an actual schedule — meaning you go to bed and wake up around the same time every day. Doing so will help you sleep all the way through the night, according to Harvard sleep specialist Patrick Fuller.

4. Are you drinking more than two caffeinated beverages a day?

If you can't get by without multiple coffees, you might need to go to bed earlier. REUTERS/Adeel Halim

Caffeine isn't a bad thing. In fact, coffee consumption has been linked to a lower risk of many diseases, though nutrition pros will tell you to watch how much cream and sugar you add. But relying on coffee to get through your day doesn't say great things about your sleep habits, according to Breus.

"You may want to look at how many caffeinated beverages or energy drinks you take in during a day," he said. "Anbody who drinks more than two caffeinated beverages during the day is tired."

5. Do you have frequent cravings for fatty, carb-heavy foods?

Breus said that a lack of sleep may also contribute to cravings for high-fat, carbohydrate-rich foods. When we're sleep deprived, he explained, our bodies are coursing with adrenaline and stress hormone cortisol. Eating fat- and carbohydrate-rich foods can trigger the release of a calming brain chemical called serotonin.

"The brain doesn't like it when your cortisol is high for an extended period of time," he said. "So it triggers a craving to make you eat a doughnut, for example. Serotonin spikes, which calms down cortisol."

Remember that cravings aren't inherently evil— and you shouldn't feel guilt over indulging in treats now and again. But Breus said that frequent late-night cravings for fatty, carb-heavy foods could indicate sleep deprivation.